Dual dump gate construction



n- 1 B. s. CZAPIEWSKI 3,298,745

DUAL DUMP GATE CONSTRUCTION Filed June 2, 1965 5 Sheets-Sheet 1 1 N VIZN T0 R BlLLY S. CZAPHZWSKI flww w w waww Jan. 17, 1967 I B. s. CZAPIEWSKI 3,298,745

DUAL DUMP GATE CONSTRUCTION Filed June '2, 1965 v s Sheets-Sheet 2 INVENTOR.

BlLLY S. CZAPHEWSKI Y BY ATT'YS n- 1967 B. s. CZAPIEWSKI 3,298,745

DUAL DUMP GATE CONSTRUCTION Filed June 2, 1965 5 Sheets-Sheet INVENTOR;

8mg '5. CZAPEWSKI 9044502 ATT'YS United States Patent 3,298,745 DUAL DUMP GATE CONSTRUCTION Billy S. Czapiewski, Omaha, Nebn, assignor to Omaha Body & Equipment Company, Omaha, Nebn, a corpo ration of Nebraska 1 Filed June 2, 1965, Ser. No. 460,788 Claims. (Cl. 29837) This invention relates to dual dump gate construction, and, more particularly, to a discharge mechanism for use with bottom dump trailers;

Fill-dirt (earth) and similar cohesive or adhesive materials have a high angle of repose, requiring extraordinarily large area dump gates in relation to the hopper areas containing the load mass. This is to prevent bridging of the load, which restricts or prevents the release of the material when the gates are opened for dumping. The resulting large gate area in contact with the load sets up excessive friction which must be overcome when opening the gates for dumping. The power, requirements for opening large area gates against the excessiveload friction usually exceed that which is available. It is, therefore, 'an object of this invention to provide a gate construction which overcomes this drawback. More particularly, it is an object .of the invention'to provide a dual gate construction which uses the natural bridging characteristics of material to relieve the movable, powered gates of most of the load until they are partially opened, thereby greatly reducing the power requirements and permitting fast and clean dumping of the hoppercontents. In this manner, the inherent disadvantage of prior art practices has been converted to an asset.

Another object of the invention is to provide a dual dump gate construction wherein unique mechanical means are provided for sequential gate opening whereby a discrete opening movement of outer gates actuates inner gates to open and relieve a bridged condition of the cohesive material.

Yet another object of the invention is to provide a dual dump gate construction wherein uniquely arranged and'shrouded power means are provided for sequentially opening the gates.

Other objects and advantages of the'invention may be seen in the details of construction and operation set down in this specification.

The invention is explained in conjunction with an illustrative embodiment in the accompanying drawing, in which:

FIG. 1 is a perspective view of a trailer equipped with gates constructed according to the instant invention;

FIG. 2 is an enlarged fragmentary perspective view of a portion of the trailer showing the gates in open position;

FIG. 3 is a view similar to FIG. 2 but showing the gates in closed condition;

FIG. 4 is a fragmentary end elevational view of the trailer body showing the gates in closed position;

FIG. 5 is a view similar to FIG. 4 but showing the gates in partially opened condition, i.e., the lower or outer gates being partly open while the inner or upper gates are still closed;

FIG. 6 is a view similar to FIGS. 4 and 5 and constitutes a later condition of the elements in the sequence of opening wherein both sets of gates are in open condition;

FIG. 7 is an enlarged fragmentary sectional view such as would be seen along the sight line 7-7 applied to FIG. 4;

FIG. 8 is a fragmentary perspective view of the power means for opening the gates and in a condition corresponding to the gates being open;

3,298,745 Patented Jan. 17, 1967 FIG. 9 is a view similar to FIG. 8 but wherein the parts are arranged in the condition they maintain when the gates are closed; and FIGS. 10-12 are schematic sectional views of the gate construction showing the three stages of operation corresponding to FIGS. 4-6.

In the illustration given and with particular reference to FIG. 1, the numeral 20 designates generally a trailer for the transportation of dirt or like cohesive material susceptible of bridging and therefore diificult to dump. The trailer '20 includes a hopper-like body 21 and a wheeled trailer carriage 22. The forward end of the trailer 20 is equipped with a hitch portion 23.

In FIG. ,1, the numerals 24 designate outer gates on one side of the trailer which are actuated by power means 25, it being appreciated that a second set of gates cooperating with the gates 24 is located on the opposite side of the trailer but not seen in FIG. 1. The particular trailerillustrated-in FIG. 1 has two compartments within the hopper body 21 occasioned by the interposition of the transverse wall 2 6. It will be appreciated that a greater or lesser number of compartments, and thus series of gates, may be. utilized within the practice of the invention.

Operation in general It-is believed that the invention-can be more quickly understood by first considering the operation in general and by reference to the schematic showing in FIGS. 10-12. In FIG. 10, the numeral 21 again designates a hopper body, and a load L is confined within the hopper body, being supported in part bythe lower gates 24 and an upper pair of gates each designated 27. It will be noted that the gates 27 do not close completely and that the closure of the open bottom of the hopper is provided by the coaction of the two gates 24. However, the gates 27 advantageously support the load L in a bridge fashion.

Turning now to FIG. 11, it will be noted that the lower gates (now designated 24) are partly open so as to permit a portion of the load L to be dispensed while the remainder of the load L remains in the well known bridge fashion. The gates 27 in FIG. 11 correspond in position to the gates 27 in FIG. 10.

Turning now to FIG. 12, it will be noted that now the outer gates (now designated 24) have swung fully open and that the inner gates (now designated 27 have likewise swung from the original inwardly-angled configuration to a generally vertical configuration. This results in a change in character of the load to the reverse of bridging, and this is designated by the symbol L. Thus, when the outer gates 24 are approximately halfway open-to the position 24' shown in FIG. 11-the inner gates are caused to open, releasing the bridged mass and permitting it to collapse and fall in the manner schematically depicted in FIG. 12.

The means for opening the outer gates 24 will now be described and with reference to FIGS. 4-6. In FIG. 4, the numeral 25 again designates generally the power means for opening the lower gates. In the illustration given, this takes the form of a cylinder and piston rod unit 28, optimally of the double-acting type, with the cylinder portion of the unit being supplied through lines 29 and 30 (so designated only relative to the left-hand unit in FIG. 4). For the purpose of supporting the unit 28 and the gate construction generally, the hopper body 21 is equipped with a generally rectangular discharge portion or throat as at 31. The throat 31 can also be readily appreciated from a consideration of FIGS. 2 and 3. Along a pair of opposite sides as at 32 and 33, the throat 31 is equipped with a mounting bracket 34 (better seen in FIGS. 8 and 9). The bracket 34 may be weldably secured to a the side walls 32 and 33, and it is seen that each bracket 34 is .generally channel-shaped.

Still referring to FIGS. 8 and 9, it will be noted that the bracket 34 adjacent its lower end is equipped with a pivot rod 35 for supporting the butt end of the cylinder and piston rod unit 28. The piston rod 36 of the unit 28 is pivotally connected as at 37 to a lever member 38. The lever member 38 is also channel-shaped and acts as a shroud to protect the unit 28 while functioning to interconnect the unit 28 with its associated gate 24. For this purpose, the lever member 38 is pivotally mounted by means of a rod 39 on the bracket 34 and at its other end is equipped with a pair of links 40 which pivotally interconnect the lever member 38 with the associated gate 24. The links 40 are threaded to adjust the travel of the gates 24, it being appreciated that the gates 24 are intended to come to a fully closed condition as seen in FIG. 4.

In the operation of the power means 25, it will be seen that the piston rod 36 in extending to the position designated 36' in FIG. causes the lever member 38 to pivot outwardly to the condition designated 38 and the link 40 to be pivoted clockwise to the position 40' in partially opening the gate 24 (designated 24' in FIG. 5). Further extension of the piston rod 36 results in the fully open condition which is shown in FIG. 6 and wherein like numerals are employed but with the application of a double prime (36" for the piston rod, 38 for the lever member, 40 for the link, and 24" for the bottom gate). The closure is achieved by retracting the piston rod, i.e., proceeding from the showing in FIG. 6 through that of FIG. 5 to that of FIG. 4. This arrangement has'the further advantage of locking (over-center) linkage which locks the gates in closed position even should air pressure be lost, thus preventing accidental dumping of the load. Further, it is appreciated that this construction isolates the air or hydraulic cylinder from the material being hauled and dumped.

The gates are advantageously controlled from the truck cab or other remote position through solenoid valves or other mechanically-actuated means (not shown).

Incident to the opening and closing of the outer gates 24, the inner gates 27 are likewise actuated, and the mechanical arrangement for this purpose will now be described.

Inner gate operation The actuation of the inner gates 27 (as from the closed position designated 27 in FIG. 3 to the open position designated 27" in FIG. 2) is achieved through an over-center bell crank mechanism generally designated 41. The mechanism 41 moves from the first position shown in FIGS. 4 and 5 to the second position designated 41" in FIG. 6. This is achieved by an actuator pin or post 42 provided on the associated gate 24. Referring to FIG. 3, it will be noted that the outer gate 24 is defined by a bottom portion 43 and upstanding side portions 44 (only one of which is shown in the sectional view), thus defining an essentially C shape in side elevation. The upper ends of the upstanding or arm portions 44 are pivotally connected as at 45 (still referring to FIG. 3) on the outside of the connective wall 46 of the throat 31. Advantageously, the throat 31 is rectangular, being defined by opposed walls 32 and 33 (see FIG. 4) which are joined by the connective walls 46 (only one of which is seen in FIG. 3). Thus, the actuator pin 42 extends inwardly of the arm portion 44 for engagement with the bell crank mechanism 41.

The bell crank mechanism 41 includes an L-shaped crank 47 (still referring to FIG. 3), which is pivotally mounted on the wall 46 by means of a rod 48 (see also FIG. 7). One end of the L-shaped crank 47 is pivotally connected as at 49 to a link 50 which in turn is pivotally connected to the lower end of the associated gate 27 by means of a transverse rod 51 (compare FIGS. 4, 7 and 3).

Each gate 27 is pivotally hinged as at 52 (see FIGS.

2-4) on the inner surface of the sides or walls 32 and 33. In operation, the partial opening of the gate 24 to the condition 24 illustrated in FIG. 5 brings the actuator post 42 into engagement with the crank 47. Further opening of the gate 24to the position 24" of FIG. 6causes the crank 47 to assume the position designated 47" in FIG. 6. Only a slight movement of the posts 42 after engagement with the crank 47 is required to pivot them over-center, whereupon the weight of the gates 27 and the load of the bridged mass L thereon causes the gates 27 to rapidly open to the configuration 27" seen in FIG. 6.

Reverse action, i.e., closing of the inner gates 27, is achieved through a second post 53. The post 53 moves from its remote position (relative to crank 47") as seen in FIG. 6 to a position of moving engagement resulting in the ultimate pivoting over-center of the crank 47 to return to the FIG. 4 position. The crank 47 has its other arm portion, i.e., the one not connected to the link 50, arranged to abut a stop 54 (see FIG. 4) at the completion of the closure movement.

I also find it advantageous to provide an equalizer mechanism generally designated 55 (see FIG. 4), which includes a lever 56 pivotally mounted on the connective walls 46 and which is interconnected by means of links 57 and 58 to the two outer gates 24.

The manner of supporting and locking the gates may be varied depending upon the type of material handled. In some cases the bridging may be used to advantage and thereafter destroyed through employment of only one pivotal inner gate, or by developing a mutual lock.

While in the foregoing specification a detailed description of an embodiment of the invention has been set down for the purpose of illustration, many variations in the details herein given may be made by those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. A dual dump gate construction, comprising a hopper having an open bottom, the first pair of co-acting gates pivotally mounted on said hopper for closing said open bottom, means on said hopper for opening and closing said first pair of gates, a second pair of co-acting gates pivotally mounted in said hopper partially closing said open bottom to temporarily support a bridged mass during initial opening of said first pair of gates, and means on said first pair of gates for opening said second pair of gates during the opening of said first pair of gates including an over-center bell crank on said hopper normally maintaining said second pair of gates in said partially closed position and lug means on said first pair of gates for upsetting said bell crank.

2. The structure of claim 1 in which said means for opening said first pair of gates includes a cylinder and piston rod unit for each of said first pair of gates, a channel-shaped lever member pivotally mounted on said hop per at one end and at the other end connected to one of said first pair of gates, said unit being interconnected between said hopper below said lever and an intermediate portion of said lever member, whereby said lever member is in shrouding relation with said cylinder and piston rod unit.

3. The structure of claim 2 in which an over-center linkage is interconnected between said lever member other end and the associated one of said first pair of gates whereby said first pair of gates is locked in a closed condition to prevent accidental dumping of a load.

4. A dual dump gate construction for a gravity discharge body having an open bottom, comprising a generally rectangular throat-like frame providing a bottom outlet for said body, a first pair of gates pivotally secured to the exterior of said frame and cooperative to close said open bottom, each gate of said first pair being generally C-shaped to provide upstanding arm portions pivotally secured at their upper ends to said frame, a second pair of gates pivotally mounted at their upper ends within said frame for only partially closing said open bottom, the lower end of each of said second pair of gates being equipped with a linkage mechanism pivotally connected to said frame, said arm portions being equipped with means for actuating said linkage means to thereby open said second pair of gates after a limited opening movement of said first pair of gates.

5. The structure of claim 4 in which said linkage mechanism includes an L-shaped bell crank pivotally mounted on said frame and a link connecting one end of said bell crank with the lower end of its associated one of said second pair of gates, said actuating means including a pair of posts operative to move said L-shaped crank overcenter for gravity dumping and supported locking, respectively.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 10/1940 Germany.

BENJAMIN HERSH, Primary Examiner. 15 RICHARD J. JOHNSON, Examiner. 

1. A DUAL DUMP GATE CONSTRUCTION, COMPRISING A HOPPER HAVING AN OPEN BOTTOM, THE FIRST PAIR OF CO-ACTING GATES PIVOTALLY MOUNTED ON SAID HOPPER FOR CLOSING SAID OPEN BOTTOM, MEANS ON SAID HOPPER FOR OPENING AND CLOSING SAID FIRST PAIR OF GATES, A SECOND PAIR OF CO-ACTING GATES PIVOTALLY MOUNTED IN SAID HOPPER PARTIALLY CLOSING SAID OPEN BOTTOM TO TEMPORARILY SUPPORT A BRIDGED MASS DURING INITIAL OPENING OF SAID FIRST PAIR OF GATES, AND MEANS ON SAID FIRST PAIR OF GATES FOR OPENING SAID SECOND PAIR OF GATES DURING THE OPENING OF SAID FIRST PAIR OF GATES IN- 